The son and daughter of a Medford man who was fatally shot Monday in White City say they are baffled by reports their father was acting erratically and crying out for help.

"Nothing really makes sense," said Mark Corsbie Jr., the 20-year-old son of the dead man, Mark Anthony Corsbie. "This is something totally out of the ordinary."

The 49-year-old Corsbie was shot to death as he was forcing his way into a house at 7898 Andrea Drive in White City at about 1:30 p.m., according to Jackson County sheriff's deputies.

Just before the shooting, he was reportedly crying for help and pounding on front doors on Avenue E, which crosses Andrea Drive, investigators said. Detectives are trying to determine whether mental health issues, drugs, alcohol or other circumstances contributed to the behavior.

Corsbie's daughter, Amanda Corsbie, said he had previously been diagnosed as a paranoid-schizophrenic.

A preliminary investigation by the Sheriff's Department has determined the father was shot with a single round from a .357-caliber revolver. The resident of the house, a 66-year-old man identified by friends as Norm Thomas, was protecting his home and his daughter and grandson and was acting in self-defense, the preliminary investigation has found.

Corsbie's son said he has no idea why his father, who lived in east Medford, would be in White City, and is disturbed that the situation escalated to the point where his father was shot.

"I am still in shock," he said.

Corsbie said that in general his father didn't exhibit any unusual behavior over the past few months.

"This is something totally out of the ordinary," he said.

Mark and Amanda, 17, said their father apparently made an inadvertent "pocket" call to Mark's cellphone about an hour before the shooting in which he could be heard frantically pleading with a young woman for help.

"He was crying, begging for them to stop hurting him," Amanda said.

While deputies have so far concluded that only one bullet struck her father, Amanda said a detective told her that he had been hit with two bullets.

"To shoot my dad in the heart and head is cold-blooded," she said. "It is murder. Me and my family have to bury my dad."

The elder Corsbie had a record and was sentenced in 2004 to nearly six years in prison for a second-degree robbery conviction in Jackson County. He was divorced in 2011 and his second wife filed a restraining order against him in March and later filed for divorce.

Amanda said her father, who worked at a gas station in Ashland, had been diagnosed as a paranoid-schizophrenic while in prison, but she said she didn't think that would explain why he was so upset prior to the shooting.

She wondered why, if his behavior was so erratic, anyone would open the door of their home.

"If the man was that scared of him, he would not have opened his door," she said.

Amanda said her father had been going out with "random" people since Sunday, which she said was out of character for him.

She also doesn't know why he ended up in White City.

"My dad never had friends," she said. "He was a family man. Family was the most important thing to him."

Amanda said her father lived at their house in east Medford.

"Me and my brother were close to our dad," she said. "We are like the three musketeers."